This invention is in the field of electromechanical systems, and relates to the use of buoyant aircraft (such as zeppelins filled with hydrogen or helium) with spinnaker-type sails to generate electric power.
Several terms that apply to buoyant aircraft should be briefly addressed. These terms overlap heavily, and any of them can be applied to the types of buoyant aircraft of interest herein. However, several of these terms have potentially misleading connotations, and therefore should be avoided.
Technically, the buoyant aircraft of interest herein can be called “balloons”, since they will have flexible enclosures (which also can be called envelopes, bags, skins, bladders, or similar terms) that can be reversibly inflated and deflated. However, in the context of buoyant aircraft, “balloons” tends to imply hot air balloons with spherical rather than elongated shapes, so “balloon” is not preferred for use herein.
These buoyant aircraft also can be called “blimps”, which indicates a flexible fabric-type outer skin (or envelope, bladder, etc). However, “blimp” also can imply that the outer skin will be completely collapsible, in ways that allow convenient storage and transport on the ground. Since the aircraft of interest herein must have stiff and strong internal frames (also called skeletons, spines, or other terms), they will not be collapsible. Therefore, “blimp” is not preferred.
The term “dirigibles” derives from a French word for “steerable” or “directable”. It applies to any buoyant aircraft with an elongated streamlined shape designed for powered and steerable flight through the air. However, since “dirigible” is a dissonant word that does not sound appealing or translate well, and since the aircraft herein are designed to be blown by the wind while tethered to the ground, rather than flown and steered under their own power, it also is not preferred for use herein.
The term “zeppelin”, named after a German engineer who created several major advances in design and construction of such craft, indicates (in modern usage) that multiple gas-tight compartments will be used to hold the hydrogen or helium, so that if one or more compartments are breached, the buoyant gas that remains in any intact compartments will enable a controlled (or at least slower) descent, for greater safety. It has an interesting sound, it is easier to pronounce than dirigible, and it has acquired additional social connotations from the rock band, Led Zeppelin. Accordingly, “zeppelin” is used herein as a generic term for the types of buoyant aircraft that are of interest herein for generating electric power.
To distinguish a “zeppelin” or other “buoyant aircraft” that can be used to generate electric power as disclosed herein, from various types of toys, amusements, prototypes, weather balloons, or other smaller buoyant balloons or devices, the term “buoyant aircraft” as used herein is limited to devices that can exert a vertical lifting force of at least 5 tons, when measured at sea level. As noted below, if a buoyant aircraft can lift five tons vertically, then it can pull a wheeled car that weighs more than 5 tons up a sloping track on the side of a hill or mountain.
There is substantial art in the field of designing and using zeppelins to lift heavy items, with two examples offered by the “Cargolifter” and SKYHOOK™ systems. The Cargolifter system was a giant zeppelin with a set of cables and winches on the bottom, and a set of propeller engines that could move it slowly and horizontally through the air. It was designed for transporting cargo, by means that generally involved using the cable and winch system to lift a large and heavy item off the ground to a low suspended altitude, and then using the propeller engines on the zeppelin to carry the cargo to a desired location, where it would be lowered. That company did not succeed. Hundreds of millions of dollars that had been invested in it disappeared under mysterious circumstances; the company went out of business; and a huge hangar that was built for the zeppelin was converted into an indoor amusement park in Germany. Various pictures and information concerning it remain available, on the Internet.
That failed attempt stimulated renewed interest in using buoyant aircraft to transport cargo, and the SKYHOOK™ system, developed jointly by Boeing and by Skyhook International Inc. of Canada, resulted. This system comprises a zeppelin with a cable and winch system on the bottom, and with four large propeller engines, mounted at the ends of rotatable struts that extend out from the body, positioned at locations comparable to the tires on a car. Illustrations, press releases, and more information can be found by searching the Internet for “skyhook”; however, it is not clear whether any such units have been actually sold, or whether they are in actual use.
Another proposed design worth noting is the “Stratellite” system, which involves a buoyant craft designed to operate as a communications system in the upper stratosphere, at about 80,000 feet, with the goal of providing a relatively low-cost midpoint between orbiting satellites, and very tall antennas. It is shaped like a relatively wide and flat whale, to provide it with a large top surface that is designed to hold photovoltaic materials, to generate solar-powered electrical energy, to run and support the amplifiers, switches, routers, and other electronic systems that will be carried and provided by the zeppelin. Information on that system is available via Wikipedia, Google, and other Internet sources. It does not appear to be in commercial use, and questions arise about whether it is practical, in view of the high winds in the upper atmosphere (which presumably would keep such a system constantly moving), and the vulnerability of polymers in an envelope to damage and degradation by ultraviolet radiation, which is much stronger at such heights than at ground level.
None of those systems are designed or intended for a repeated and frequent cycling operation, in which helium or hydrogen gas is cycled back and forth between high-pressure tanks, and a low-pressure zeppelin envelope. Accordingly, the closest prior art known to the Applicant herein is believed to reside in a prior issued patent, and a prior published application, by the same inventor herein.
Buoyant Zeppelins for Lifting and Launching Large Rockets
The Applicant herein initially became interested in buoyant aircraft (such as blimps, dirigibles, and zeppelins), because of a method that occurred to him for lifting large and heavy rockets high into the atmosphere, and getting them flying forward at moderate speeds, before any rocket fuel must be burned.
One of the crucial factors, for any rocket that is designed to reach an orbital height and speed, is its “orbital efficiency”. That number is calculated by dividing the total weight of all hardware and fuel that will reach orbit, by the total weight of the fully-loaded rocket when it was sitting on a launchpad. For conventional rockets launched from the ground, orbital efficiencies reportedly range from about 1% for small orbital rockets, to about 4% for very large Saturn-class rockets. As demonstrated by the huge fireballs that are created and released when a large rocket must lift its entire weight off of a launchpad, from a stationary start, much of that rocket fuel is burned just to get the rocket started, and to lift the fuel. Accordingly, if a system can be devised for lifting a rocket up to 40,000 feet, and getting it flying forward at 500 to 1000 miles per hour before any rocket fuel needs to be burned, then that system would appear to be capable of increasing orbital efficiency levels to somewhere between 20 and 30%, which is roughly a ten-fold increase over the current methods.
Accordingly, the Applicant herein described and patented a “lift and launch” system, for rockets large enough to reach orbit or travel to the moon or Mars. As described and illustrated in U.S. Pat. No. 7,131,613 (Kelly), that system includes a “vertical stack” of four subassemblies, or layers, each of which plays a different role during a rocket launch.
The top layer contains at least one zeppelin, and preferably at least three or more zeppelins held together by strong cables in an “array”. The cables will not be attached to the skins of the zeppelins; instead they will be secured to strong internal frame components (which can also be called skeletons, spines, etc.). During a slow vertical ascent, the zeppelins will be fully inflated. After the complete assembly reaches a release altitude, the zeppelins will be partially deflated, in a manner that provides them with streamlined shapes, to allow forward flight at a modest speed in the thin upper atmosphere. Telescoping vertical and horizontal struts inside the zeppelins will be extended and retracted in a coordinated manner, to create a shape that will resemble either: (i) a typical fish, if the vertical struts are extended while the horizontal struts are retracted; or, (ii) a stingray or manta ray, if the horizontal struts are extended and the vertical struts are retracted. Either streamlined shape can reduce drag, and can enable forward flight at a modest speed, even while a large quantity of gas remains inside the zeppelin(s) to help provide “lift” while forward flight is being established.
The second layer of the four-layer system for lifting and launching rockets comprises a “tank barge”, which will carry pumps and high-pressure tanks. When the entire system reaches or approaches its maximum altitude, the pumps carried by the tank barge will be switched on, and they will partially deflate the zeppelin(s), in a manner that transfers a portion of the helium or hydrogen into high-pressure tanks carried within the tank barge. For additional lifting power and control, each tank barge presumably also should have at least four rotatable wings, with two wings on each side of the body of the barge, mounted fore and aft. The engines for the “tank barge” wings should be selected for efficiency rather than speed, and presumably should have oversized propellers, comparable to the propellers used on “VTOL” (vertical take-off and landing) aircraft, such as the Osprey aircraft used by the American military. As with VTOL aircraft, the rotatable wings of a tank barge, in a lift-and-launch system for rockets, will be mounted on horizontal axles that pass sideways (transversely) through the body of the tank barge; this will allow each wing to be rotated, not in an entire circle, but through a 90 degree arc that allows each wing to be either vertical (for generating lift, during ascent), or horizontal (for generating forward thrust, during flight). Accordingly, during ascent, when the wings of a tank barge are rotated to a vertical position, the large propellers driven by the tank barge engines will function in a manner comparable to the rotor blades of a helicopter. Providing at least four such engines, distributed around the periphery of the tank barge, will provide greater balance, stability, and control for the lifting system.
The third “layer” of this system will comprise a “winged ferry” (or lifting ferry, flying ferry, or any other suitable term). It will have either fixed or rotatable wings, and it presumably will have jet engines that can reach much higher speeds than propeller engines. This unit, initially carrying a loaded rocket beneath it, will power up its engines and help establish forward flight, at a low to moderate speed, while remaining suspended beneath the tank barge and the zeppelins.
The fourth and bottom layer of the system will be a rocket, suspended horizontally below (and aligned with the fuselage of) the “winged ferry” plane. Since the rocket will initially operate while still in the atmosphere, it can be provided with wings or fins, and/or with a combination of jet and rocket engines.
The complete four-layer system is designed for a slow, safe, and gentle ascent to an altitude somewhere between 30,000 and 60,000 feet, using the combined lifting forces provided by the buoyant zeppelins, and the tank barge engines acting like helicopter rotors. Once a release altitude has been reached, the bottom two subassemblies (the “winged ferry” and the rocket) will be separated and released from the top two subassemblies (the zeppelins and tank barge). The ferry and rocket will begin flying forward on a downward-sloping glide path until they reach high speed, unhindered by the zeppelins or tank barge. Just before the rocket is released, its power and thrust will be increased, and the wings, flaps, and fins of those two units, still flying together, will be used to lift their noses upward to a steep slope, to provide a near-optimal launch direction, for the rocket.
Meanwhile, the tank barge will continue to deflate the zeppelins, and those two units, still coupled to each other and flying together, will descend back to a landing spot, using the engines and wings of the tank barge for power and steering.
Accordingly, by using that type of lift-and-launch system, a large and heavy rocket can be lifted to an altitude of greater than 30,000 feet, and can reach forward flight at a speed of hundreds or even thousands of miles per hour, before a single drop of rocket fuel must be burned.
In terms of prior art, this patent discloses a system of zeppelins that are tethered to a tank barge carrying pumps and high-pressure tanks, specifically for the purpose of enabling a repeating cycle of ascent and descent by one or more zeppelins, for lifting a heavy weight (i.e., a fully-loaded rocket) to a desired altitude, and for then returning the zeppelin system to the ground so that it can be prepared for the next launch. It also states that the pumps/compressors and high-pressure tanks can be carried directly by the zeppelin, if desired, in a way that can eliminate one of the four layers of the complete lift-and-launch system; however, that design would not be optimal, and it would eliminate and lose a set of useful components that can help the system make a high-altitude transition from slow ascent, to high-speed flight.
Lifting Ferries for Cargo or Passenger Planes
After working on the rocket system described above, the Applicant herein realized how a similar system could be modified for use in lifting conventional airplanes (such as passenger jets) up to a takeoff height or even cruising altitude, before releasing them. This type of lifting system can use a “lifting ferry” that comprises two levels: (i) an array of zeppelins, filled with hydrogen or helium; and, (ii) a “lifting ferry” with pumps and high-pressure tanks, and with wings that can be rotated between a vertical position (for ascent) and a horizontal position (for forward flight). When those two lifting assemblies, acting together, have lifted a cargo or passenger plane to a suitable altitude (which in most cases will range between 10,000 and 30,000 feet), the engines of the plane will be started and/or powered up, while the zeppelins are partially deflated to convert them into a streamlined shape, and the wings of the lifting ferry are rotated partially forward, to establish a modest forward flight speed.
When the combination of forward flight speed and plane engine thrust have reached a safe level, the entire system will be angled downward, into a “nose down” position that establishes a “glide path” for safe release of the airplane. The plane will be released, and it will rapidly increase its flight speed, allowing it to level off and fly normally to its destination. The “lifting ferry” will descend back to earth, with the zeppelin(s) still coupled to the rotatable-wing aircraft, to be prepared for another ascent with a different fixed-wing airplane.
That system is believed to be capable of substantially reducing the quantity of fuel that must be used by fixed-wing aircraft to take off from a runway. It is described in more detail in copending patent application Ser. No. 11/557,378, filed Nov. 7, 2006 and published as 2007/0187547. The contents of that application are incorporated herein by reference, as though fully set forth herein.
Coupling of Two Different Types of Power Cycles
While considering and analyzing various design requirements, operating principles, and efficiency advantages for the type of “lifting ferry” that can lift a fixed-wing airplane up to a release height, the Applicant realized that a curious and possibly paradoxical effect might arise, when two different types of systems are compared against each other. One type of system comprises a buoyant zeppelin, combined with a “lifting ferry” with rotatable wings and oversized propellers. The other type of system comprises a “lifting ferry” only, with rotatable wings and oversized propellers, but without a zeppelin.
A comparison between those two different types of “lifting ferry” systems suggests that inclusion of a buoyant aircraft that uses a repeating cycle (i.e., gas expansion and zeppelin inflation for each ascent stage, followed by gas compression and zeppelin deflation for each descent stage) may be able to provide a substantial improvement in the operating efficiency of such a lifting system. Stated in other words, it appears that the total amount of aircraft fuel that must be burned, on a “per passenger-mile” basis, can be reduced, by including a buoyant aircraft (such as a zeppelin filled with hydrogen or helium, and provided with pumps and tanks that can partially deflate the zeppelin and convert it into a streamlined shape with reduced buoyancy, after it reaches a desired altitude) in the lifting ferry.
The extent of the increased improved lifting efficiency that can be gained, by incorporating a buoyant craft such as a zeppelin in a lifting ferry, cannot be reliably estimated or predicted by the Applicant, who does not have the computer-modeling resources that are available to aircraft companies and engineering colleges. However, even without computer modeling, an important factor came into focus, which can be described as follows.
When a gas is run through a repeating cycle of compression and expansion, the result (in terms of the net energy input that is required, to keep the cycle running) is believed to be similar to various other types of repeating cycles, such as: (1) compressing a metal spring, which will require energy input, leading to a state of higher “stored energy”; then, (2) allowing the spring to expand again, which releases the “stored energy”. If the stored energy that is released by the spring, during expansion, can be “grabbed” (or harvested, extracted, etc.), and either stored briefly, or converted into some alternate type of energy which will then “swing back” again as the cycle continues, then that type of cycle can continue to run, over and over again, with only low net energy input requirements.
Stated in other words, it requires substantial energy input to reach a complete first compression of a spring, which is necessary to get the cycle started. However, assuming that the spring was made from a well-chosen alloy, after a first peak of high “stored energy” has been reached, then from that moment on, the spring can continue to oscillate back and forth in a repeating cycle, without consuming a large amount of energy, as it merely repeats the cycle.
Using another analogy, if a large and heavy pendulum has received enough energy input to get it swinging through an arc, then it may continue swinging for hours, with no additional energy, power, or work input. For purpose of analysis, assume that a new cycle begins each time the pendulum reaches a point of maximum height, at the farthest “reach” of its arc. At that instant, the pendulum comes to a pause; it is stationery, as it reverses direction. At that instant, there is zero “kinetic” energy, and zero momentum, and the energy in the pendulum can be referred to as stored energy (or potential energy, or similar terms), which is manifested in the fact that the pendulum has traveled to the highest point (or altitude, elevation, etc.) in its arc. Then, as the pendulum swings back down through its arc, its stored or potential energy is converted into kinetic energy (i.e., speed and momentum), until the pendulum passes through its low point, at the center of its arc, where it reaches its maximum speed, momentum, and kinetic energy. As soon as the pendulum has passed that lowest point, gravity begins working against the kinetic energy, in a manner that slows down the pendulum, until it comes to a complete and total stop, at the “far end” of its arc. That “half cycle” is then repeated, as the pendulum swings back in the opposite direction, arriving at a stopping point that is usually only a very tiny or even microscopic fraction of an inch lower than its highest point of elevation during the previous cycle.
The point worth noting is that once a large and heavy pendulum is pushed up to a relatively high point and then released, so that it will begin swinging, it can keep swinging for a long time, through hundreds or even thousands of arcs (depending on its length, weight, etc.), with absolutely zero requirements for any additional input of energy, power, or work. In mechanical systems, that usually is the nature of a repeating or reciprocating cycle, if a system is able to convert energy levels back and forth between two different states, without substantial losses of energy during each conversion.
A similar phenomenon applies to “hybrid” cars. In a typical non-hybrid car, the brakes do nothing to harvest any useful work or power. Instead, brakes stop a car by using friction, which heats up the brake pads and wheel rotors; those brake pads and rotors then dissipate that useless heat, to the atmosphere. When a stopped car begins moving again, it must burn additional gasoline, to provide the power that accelerates the car back up to driving speed.
In contrast, “hybrid” cars get better gas mileage because they convert the kinetic energy, of a moving car, into stored electrical energy, each time the brakes are applied and the car slows down or comes to a stop. Instead of simply pressing brake pads against wheel rotors, the braking system of a hybrid car engages an electric power generator. As known to any engineer, a generator will “push back” when a wire coil is mechanically forced to rotate, inside a magnetic field. The generator in a hybrid car that is slowing down converts kinetic energy into electric power, which is sent to a storage battery. Then, the electric power stored in the batteries is used as a power supply, to accelerate the car up to driving speed, when the driver pushes the “gas pedal” again. Stated in other words, hybrid cars are more fuel-efficient because they cycle energy back and forth between two different useful energy states, rather than wasting energy by heating brake pads and wheel rotors, each time a car must stop or slow down.
In a directly analogous manner, if a repeating cycle of gas compression (into high-pressure tanks carried by a “tank barge”) and expansion (into the low-pressure envelopes of floating zeppelins) is carried out by a pumping system that is designed to capture and convert energy back and forth between two different useful states, rather than having to “start the work all over again” each time the “compression leg” of a cycle begins, then that type of pumping system should be able to continue for numerous cycles, with only relatively low requirements for additional input of power, energy, and work, to keep the cycle going.
That operating principle—it does not require large inputs of energy and work to keep a repetitive cycle going, if the cycle is carried out by efficient and well-designed machinery that converts energy back and forth between two different useful states—must now be directly compared and contrasted against a very different operating principle, which can be stated as follows.
If a large zeppelin is filled with helium or hydrogen gas, then the buoyant force created by that zeppelin can lift a heavy weight, to a very high elevation. Then, once the heavy weight has reached its highest elevation (or altitude, or similar terms), it can generate a large amount of usable electric power, as it descends back down to the lowest elevation in its reciprocating pathway.
As an example that is described in more detail below, consider a heavy weight in the form of a railroad car (or series of cars, in a train) that weighs dozens or even hundreds of tons, which travels up and down a sloping railroad track on the side of a mountain that is thousands of feet high. Assume that each railroad car weighs 50 tons (this is a feasible weight, since a large zeppelin can lift about 300 to 400 tons) and carries large, heavy, and powerful generators and batteries. As a train with several 50-ton cars rolls down that sloping railroad track, the turning of the wheels on the train cars can be used to rotate the driveshafts of the generators carried by the cars. By using rotating wire coils mounted inside powerful magnetic fields, mechanical power is converted into electric power that emerges from the generators. That electrical power can be temporarily stored in the heavy bank of batteries carried by the car. When the car reaches the bottom of its track, that electric power is transferred to a stationary power grid.
Accordingly, if those two different types of reciprocating cycles are coupled together, a potential paradox would appear to arise. One cycle involves helium or hydrogen gas, cycling back and forth between high-pressure tanks, and low-pressure zeppelins. As described above, a presumption arises that this type of reciprocating compression-and-expansion cycle likely can be performed without requiring huge inputs of additional energy from the outside, so long as the gas-handling equipment is properly designed to “harvest” and store the energy that is released each time high-pressure gas leaves the tanks. The other cycle involves lifting a large and very heavy weight to a high elevation, and then efficiently extracting the energy that is generated when that large and heavy weight rolls down a sloping track, to a point which is thousands of feet lower than the elevation of the highest point of the railway track.
The paradox that would appear to be created, when those two different types of cycles are coupled together, centers around the phrase, “perpetual motion machine”. As any competent scientist or engineer knows, perpetual motion machines cannot exist, because they would violate a basic law of physics which states that entropy must increase, in any system, over time. That law of physics is known as the second law of thermodynamics, and it is described in numerous sources that can be easily located at no cost. For example, an explanation at a layman's level is available in Wikipedia, and online materials, posted by professors for college-level courses in physics or thermodynamics, cover the subject at more advanced levels.
However, any observation that “perpetual motion machines” cannot exist must be approached carefully, and a crucial step in any such analysis is to define and understand what the relevant “system” actually is.
As a simple example, if someone couples photovoltaic cells to a battery and a motor, and places that system in a location where the sun shines on most days, then for all practical purposes, and under any realistic understanding and scenario, that simple, basic, easily-created system is indeed a “perpetual motion machine”. By using sunlight as its energy source, it can continue running until the motor wears out, or until the sun dies.
When faced with that scenario, a scientist will point out in reply, “Yes, but by bringing sunlight into the system, you make the sun a part of your system. And the sun will not last forever. Its entropy is increasing. Even though it will last for billions of years, it still is not perpetual.”
That is indeed true. The sun will not last forever; it has a projected lifespan of roughly 5 billion more years. However, on a practical and reasonable level, there is no good reason not to regard “all of planet earth” as a reasonably complete and self-contained system, and there is no compelling reason to not regard the entire future of this planet as a relevant, practical, and appropriate operating “lifetime” for a machine.
Under those types of practical and reasonable terms, it becomes simple and easy to create something that can be classified and dismissed as a “perpetual motion machine”. It can be accomplished merely by using sunlight to drive a photovoltaic cell, with no other energy input that “costs” anything in any way. Or, it can be done by using geothermal energy, or wind power, or ocean waves. None of those “external energy inputs” are limited by anything except the lifespan of the sun and the earth. For practical purposes, when plain English is used, a wind turbine is a “perpetual motion machine”. It can continue generating and releasing power for decades, without ever needing any additional energy input that humans can provide. It can generate and emit (the terms “capture and convert” might be more accurate) much more power and energy than was used to build it.
Accordingly, the levels of practical insight and understanding can improve if people use terms such as “net power output”, where the word “net” has the same meaning as in “net income” or “net profit”, rather than getting distracted by “perpetual motion machine” definitions and conundrums.
Since “net power output” will be crucial in determining whether and to what extent the invention disclosed herein is commercialized, two types of well-known power generation systems appear to offer the most relevant and useful benchmarks for evaluating and measuring the invention disclosed herein.
One line of technology involves large wind turbines, and the large units made by a company such as General Electric (GE) offer a good system for comparative analyses. Those units emerged from an extensive process of research, development, computer modeling, and optimization, and technical information on them is readily available from websites such as www.ge-energy.com/wind.
Large GE wind turbines are made in 1.5, 2.5, and 3.6 megawatt (mW) sizes. A 1.5 mW unit (which comes in a smaller 1.5sle model and a larger 1.5xle model) has a “hub height” that ranges from 65 to 80 meters (213 to 263 feet) high, and a rotor length of either 38.5 meters (126 feet) for the 1.5sle model, or 41.25 meters (135 feet) for the 1.5xle model. Either model has “variable pitch” rotors (i.e., the angle or slope of each rotor blade can be adjusted, depending on the prevailing wind speed at any moment). To generate power, the average wind speed (averaged over 10 minute intervals) must be at least 3.5 meters/second (about 8 miles per hour, or mph); that minimum speed is called the “cut-in” speed. When a “cut-out” wind speed is reached, the unit must stop generating power, to prevent damage to the unit; this upper wind speed limit is 25 meters/second (about 56 mph) for the smaller 1.5sle unit, and 20 meters/second (about 45 mph) for the larger 1.5xle unit.
For the substantially larger 3.6 megawatt units, the hub height is “site dependent” and usually ranges from about 80 to 120 meters, or roughly double the blade length of 52 meters. The minimum “cut-in” wind speed is 3.5 meters/second (about 8 mph), while the maximum “cut-out” wind speed is 27 meters/second (about 60 mph).
To spread out the expenses of coupling wind turbines to an electric power grid, multiple units usually are clustered together in banks or arrays, typically having from a dozen up to a hundred or more turbines. Because high “cut-out” speeds are important, preferred areas for “wind farms” generally require moderate and predictable wind speeds, rather than high wind speeds; suitable locations tend to be near coastlines, in valleys surrounded by hills rather than mountains, on hilltops surrounded by plains, etc. An entire “wind farm” requires large up-front investments, ranging from tens to hundreds of millions of dollars, to pay for manufacture and assembly of the turbines, and to connect the wind farm to a high-voltage power grid that supplies electricity to cities and towns. However, after those steps are complete, wind turbines can extract energy from an essentially free and unlimited resource, over an operating life that will last for decades.
The second main type of comparative or benchmark technology that merits attention involves “pumped storage hydroelectric” systems. More than 100 such units operate around the world, and information on them can be obtained by searching for “pumped storage hydroelectric” in Internet sources such as Wikipedia or Google.
These units are designed and built to help cities and towns handle an important aspect of power generation and consumption. In any city or town, the demand for electric power depends heavily on a day/night cycle. In nearly any locale, the demand and need for electric power is much greater during daytime and evening hours, starting at about 6 am (local time), and lasting until about 11 pm at night, than during the overnight hours. After 11 pm, the demand for electric power drops to much lower levels until 6 am, when demand begins to increase again.
To help cities and towns handle the day/night fluctuations in demand, “pumped storage hydroelectric” systems pump large quantities of water up to elevated tanks or reservoirs (usually sitting on hilltops), during the overnight hours of low demand, between 11 pm and 6 am. Then, to meet peak power demands during the day, the flow direction is reversed, and the water descends back down through large generators in pipes or tunnels. As in hydroelectric dams, those turbines convert the flow of pressurized water, into electric power.
Pumped storage hydroelectric units never can, and never will, reach a level that can be described as “net power out”. They will always and inevitably consume more electric power, at night, than they generate during the day. These “losses” mainly involve friction-type heating of the water, when it is pumped up a hill, and when it runs down through a pipe and turbine. Water is very efficient in soaking up and absorbing heat energy, thereby creating useless energy “sinks” that reduce the efficiency of any power-handling system that involves water. Nevertheless, because of the day/night demand cycle, pumped storage hydroelectric units are valuable and even essential to the ongoing operations of quite a few power systems, and these units offer good “benchmarks” that can be used, on a fair and practical basis, to evaluate the operating efficiencies and economic benefits of the power-generating units described herein. Because the units described herein will not suffer from any losses related to the useless heating of water, it is believed that these units can outperform pumped storage hydroelectric units, probably by substantial margins. That is sufficient to establish patentable utility for the systems described herein, regardless of whether these units operate at a “net power out” level.
Accordingly, one object of this invention is to disclose machinery and methods for generating electric power, using buoyant aircraft (with helium or hydrogen) to lift large and heavy traveling generator systems (or heavy cars coupled to generators, by cables or similar means) to relatively tall heights, thereby enabling the heavy “cars” to generate electric power as they descend down a rail-type pathway, during the descent leg of each power cycle.
Another object of this invention is to disclose and create a system for generating electric power, using buoyant aircraft that also incorporate wings, sails, propellers, or other devices, to lift heavy generator systems to relatively tall heights, thereby enabling those heavy units to generate electric power as they descend down a rail-type pathway.
A third object of this invention is to disclose a system for using fabric or polymer sails that can generate very strong pulling forces, to lift large and heavy generator units to the top of a rail-type track such as on the side or a large hill or mountain, thereby enabling those heavy units to generate electric power as they descend.
Another object of this invention is to disclose a system that couples two different cyclic processes to each other, where: (i) one cyclic process uses compression and expansion of helium or hydrogen gas; and, (ii) a second cyclic process involves lifting a large and heavy unit to the top of a rail track, and then using that large and heavy unit to generate electric power as it descends back to the lowest point on the track.
Yet another object of this invention is to disclose machinery and methods for generating electric power which have various operating advantages compared to either wind turbines, or pumped storage hydroelectric units.
These and other objects of the invention will become more apparent through the following summary, drawings, and detailed description.